1. Field of the Invention
This invention relates generally to a method to fabricate a uniform pattern of core-shell nanoparticles on a substrate.
2. Description of the Related Art
Core-shell nanoparticles comprise core nanoparticles (also called nanocrystals) of one material surrounded by a uniform shell of another material. The fabrication of core-shell nanoparticles presents numerous challenges. Current methods use either oxidation or reduction chemistry of bulk core nanoparticles, as described in C. B. Murray, et al., Annual Review of Materials Science 30 (1), 545-610 (2000). However, these methods make it difficult to process core-shell nanoparticles after they are formed, and also limits the type of materials that can be used for the shell. Another method is to deposit a film of core nanoparticles on a substrate and subsequently coat them from the top with the shell material, but this often results in non-uniform shells.
It is even more challenging to fabricate a monolayer of uniformly dispersed core-shell nanoparticles on a substrate. Such a structure has applications in making magnetic recording disks, including patterned-media disks.
What is needed is a method to fabricate a uniform pattern of core-shell nanoparticles on a substrate.